Subject: [xrblock] FW: [MMUSIC] SDP Directorate: Review of draft-ietf-xrblock-rtcp-xr-qoe-08

From: "Romascanu, Dan (Dan)" <[email-masked]>
Date: Thu, 13 Jun 2013 09:37:56 +0000

Forwarding to the WG the SDP Directorate review of draft-ietf-xrblock-rtcp-xr-qoe-08 performed by Ali C. Begen.

Thanks and Regards,

Dan

From: [email-masked] [mailto:[email-masked]] On Behalf Of Ali C. Begen (abegen)
Sent: Thursday, June 13, 2013 12:14 PM
To: [email-masked]
Cc: xrblock-chairs; mmusic
Subject: [MMUSIC] SDP Directorate: Review of draft-ietf-xrblock-rtcp-xr-qoe-08

I am the assigned SDP directorate reviewer for this draft. For background on the SDP directorate, please see the FAQ at

http://www.ietf.org/iesg/directorate/sdp.html

Please wait for direction from your document shepherd or AD before posting a new version of the draft.

Summary:
- I have a serious concern about the definition of QoE and usage of MOS in this draft.
- The RTCP XR extension syntax seems to have an issue.
- There are quite a few grammatical/capitalization/spelling errors. Please proofread the document.

Issues:

- Section 1.3: s/guideline/guidelines, s/XR Block/XR block types

- Section 1.4: s/"Audio/Video"/"audio/video", s/transport-dependent/transport-specific

- Section 1.4: I don't understand what the following sentence means:

The factors in the second category are application-specific factors that affect real time application (e.g., video) quality and are sensitivity to network errors.

- Section 1.4: s/but not limited/but are not limited

- Section 1.4: I don't generally like the term "subscriber". Use more a more generic term like end-user, client, etc.

- Section 2.1: s/8:8/S8:8

- Section 3, first paragraph: The use of "recommended". These specific (2119) keywords are not supposed to be used in lower case.

- I don't agree with the following statement:

   Information is recorded about QoE metric which provides a
   measure that is indicative of the user's view of a service.

The application cannot possibly know a user's view of service unless the user explicitly enters that info in some fashion to the application.

- Section 3.1:

I think you should replace:

The fields corresponding to unreported parameters MUST be present, but are set to zero.

With:

The fields corresponding to unreported parameters MUST be present, and MUST be set to zero.

- Section 4.1: "extmap" attribute was defined in 5285 not 4566.

- Section 4.1/4.2: Do not use "may/should/etc." in lower case. There are multiple occurrences of this.

- Section 4.1: "extmap" is already a registered attribute name. I did not understand why and in what way you want to use it.

- Section 4.2: s/indicates/indicate

- Section 4.1/4.2: Extra spaces in the SDP examples.

Replace

a = rtcp-xr:qoe-metrics = calg:1=G107,calg:2=P1202.1

With

a=rtcp-xr:qoe-metrics=calg:1=G107,calg:2=P1202.1

- Section 5.1: Use the correct registry name: "RTP Control Protocol Extended Reports (RTCP XR) Block Type Registry"

6) Section 5.2: Use the correct registry name: "RTP Control Protocol Extended Reports (RTCP XR) Session Description Protocol (SDP) Parameters Registry".